title: Attempts to reduce exposure to fungi, β-glucan, bacteria, endotoxin and dust in vegetable greenhouses and a packaging unit.
abstract: Indoor handling of large amounts of plant materials occurs in different occupational settings including greenhouses and causes exposure to bioaerosols. The bioaerosol components fungi, β-glucan, bacteria and endotoxin are involved in different airway symptoms and health effects can be dose-dependent. Therefore, there is a persistent need to reduce exposure. The aims of this study were to identify tasks causing exposure and to evaluate preventive measures aimed at reducing exposure of greenhouse workers to bioaerosols, and to study factors affecting the exposure. We have focused on different exposure scenarios; one with high short-term exposure found during clearing of old cucumber plants; the other with long-term, mid-level exposure found during tomato picking, leaf nipping, stringing up tomato plants, and packaging of cucumbers. Clearing of non-dried cucumber plants compared with clearing of dried cucumber plants significantly reduced the exposure to dust, endotoxin, bacteria, fungal spores and β-glucan. More endotoxin and fungi are emitted and more of the emitted particles were of respirable size if the leaves were dried. Along the cucumber packaging line, exposure levels were highly specific to each personal subtask. The subtask 'unloading of cucumbers' was the source of exposure making task ventilation or shielding of the process a possibility. Elimination of leaf debris on the floor reduced the exposure to fungi significantly. However, leaf debris on the floor did not contribute significantly to the exposure to dust, endotoxin and bacteria. Furthermore, to eliminate leaf debris, it had to be cleared away and this was associated with a higher exposure to dust and endotoxin. The age of the plants affected the exposure level to bioaerosols with higher exposures from old plants. In conclusion, different tasks and subtasks cause very different exposure levels. It is possible to reduce exposure by identifying subtasks causing the exposure and by modifying work processes, e.g., not drying out of plants.
authors.affiliation: The National Research Centre for the Working Environment, Lersø Parkallé 105, DK-2100 Copenhagen Ø, Denmark. Electronic address: amm@nrcwe.dk.
authors.forename: Anne Mette
authors.initials: AM
authors.lastname: Madsen
authors.forename: Kira
authors.initials: K
authors.lastname: Tendal
authors.forename: Margit W
authors.initials: MW
authors.lastname: Frederiksen
mesh_terms: D000383:Agriculture / Q000379:methods*; D018553:Cucumis sativus; D004391:Dust / Q000517:prevention & control; D004731:Endotoxins / Q000032:analysis; D004780:Environment, Controlled; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D005658:Fungi / Q000302:isolation & purification; D006801:Humans; D016014:Linear Models; D016273:Occupational Exposure / Q000032:analysis / Q000517:prevention & control*; D018515:Plant Leaves / Q000382:microbiology; D019064:Product Packaging / Q000379:methods*; D057188:Workflow; D047071:beta-Glucans / Q000032:analysis
chemical_list: D004391:Dust; D004731:Endotoxins; D047071:beta-Glucans
keywords: Bioaerosol; Cleaning; Endotoxin; Fungi; Horticulture; Occupational exposure